Combustible means for remotely arming grenades



Sept. 12, 1967 v. 1. 0| PAOLA COMBUSTIBLE MEANS FOR REMOTELY ARMING GRENADES Filed July 14, 1965 Jada/M a mefal: all! Q,//0 ,1

INVENTOR Vince/7f J D) Fae/a7 BY- J 4. 5, 5 ATTORNEY- States ABSTRACT OF THE DISCLOSURE A remotely controlled arming means for a grenade having a spring loaded arming handle and firing pin in which a length of pyrotechnic wire retains the handle and firing pin in an unarmed condition. When the wire is ignited, it will burn its entire length to release the handle and firing pin to detonate the grenade.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to the remote arming of fuzes and more particularly a means for arming a grenade, or grenades, by a pyrotechnic wire instead of the usual safety pin which holds the arming handle of the grenade in an unarmed condition. The pyrotechnic wire is strung out to a distant point from which it may be ignited. The pyrotechnic wire then burns out through the arming handle to release the arm and arm the grenade which is then fired.

With the present invention it is possible to fire several grenades in sequence which feature is especially adaptable in limited warfare and for firing non-lethal grenades or bomblets in order to harass the enemy. Clusters of these bomblets may be dropped from aircraft.

It is therefore, an object of this invention to fire a grenade, or grenades, or a cluster thereof remotely.

It is another object to replace the standard metal safety pin of a grenade by a pyrotechnic wire inserted in the grenade.

It is still another object to provide a means to permit the programmed operation of a fuzing system by utilizin-g the high strength of readily ignitable metal mixtures and alloys (in wire or pin form) and the controlled burning rate of such mixtures to attain a sequential time of events.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of the preferred embodiment as shown in the accompanying drawing in which:

FIG. 1 is a perspective view of a grenade, or bomblet, with a pyrotechnic wire inserted in the safety pin passage to hold the grenade in its safe condition;

FIG. 2 is a fragmentary perspective view of a pyrotechnic tube with a pyrotechnic wire therein and inserted through the arming handle;

FIG. 3 is an axial section through a conventional grenade firing mechanism and showing a plurality of pyrotechnic wires connected to the booster charge whereby other grenades may be fired by the ignition of its booster charge; and

FIG. 4 is an enlarged perspective of a portion of the pyrotechnic wire of this invention.

Referring to the drawing, and with reference to FIG. 1, the reference character 1 represents generally a standard type grenade, or bomblet. Grenade 1 which comprises a charge container 2 having a neck portion 3. A conventional arming and firing mechanism is indicated generally by 4.

atent The arming and firing mechanism includes a plug 5 (see FIG. 3) which is threadably secured in neck portion 3 by threads 6. Plug 5 has an axial bore 7 and a counterbore 8. A firing cartridge 9 is received in bore 7 and a booster charge 10 is contained in counterbore 8.

Container 2 is filled with the main charge 11.

The arming and firing mechanism comprises an arming handle 12 which is hinged as at 13 to plug 5 and is normally biased upwardly by a spring 14 encircling a pin 15. A firing pin 16 is also pivotally mounted on pin 15. The ends of spring 14 bear against plug 5 and the firing pin 16.

A pyrotechnic wire 17 is inserted through the usual safety pin holes 18 to hold the arming handle 12 against rotation. Holes 18 pierce walls 19 of plug 5 (one being shown) formed by a cut out portion 20 and a pair of ears 21 on handle 12.

In FIG. 3 a pair of pyrotechnic wires 22 are shown communicating with booster charge 10 and extend radially through plug 5 and neck 3 of the grenade 1 when firing of more than one grenade, or a cluster thereof, is desired. Any number of wires 22 may be employed.

In use, the grenade 1 is grasped by one hand with the thumb held against the arming handle. The other hand is used to withdraw the safety pin. The grenade is then thrown from the user which, at the same time, releases the arming handle 12 which then swings upward to free firing pin 16, held down thereby, which then pivots around pin 15 under bias of spring 14 to fire cartridge 9. The cartridge ignites booster charge 10 which when burnt through, ignites main charge 11.

This action, from the time arming handle 12 is released to actual ignition of main charge 11 requires approximately five seconds, depending upon the length of booster charge 10. Hence, there is too little time to place the grenade at a point selected for explosion thereof, since the operator would not have time to seek cover. Even if the grenade is thrown, the throw would be inaccurate for precise placement thereof.

Therefore it would be necessary to employ remote firing of the grenade from a safe distance and at a time selected.

If a non-ignitable cord was used to pull the safety pin out it might result in foul up or dragging the grenade instead of pulling out the safety pin. Hence, for small bombs like grenades, it is better to explode them by an ignitable fuze of long length rather than by using a pull cord or wire. Hence the use of a pyrotechnic wire 17 which is a braided cord filled with a mixture of high strength and readily ignitable mixture of metal and alloys to give it suflicient rigidity. This pyrotechnic wire is known as pyrofuze.

The wire 17 may be inserted in the arming handle in a single strand by doubling it as shown in FIG. 1. In FIG. 2, a roll pin 23 made of the pyrotechnic wire 17 may be inserted to give even greater strength.

In use, the conventional safety pin (not shown) is removed and the end of a pyrotechnic wire 17 is inserted. The wire is then strung out to a remote point from Which it can be ignited. The wire 17, when ignited will burn its length and when that portion which is in the arming handle 12 is burnt through, the handle 12 will be released to arm the fuze to initiate operation of the firing mechanism 4.

In FIG. 4, one or more pyrotechnic wires 22 are connected to plug 5 and in communication with the booster charge 10 of the grenade 1. These wires may be connected to other grenades to explode them when wire 17 is burnt out to fire the grenade 1. The firing of booster charge 10 will also ignite wires 22.

Grenade-s could be exploded in sequence by a wire 22 connected in turn to a preceding grenade, or clusters in a grenade dispenser.

It will be apparent that an igniting means has been devised that is adaptable for many uses. It can be utilized for the detection of fires, to operate a water deluge system for putting out the fires, alarms, etc.

While only preferred forms of the invention are shown and described, other forms of invention are contemplated and numerous changes and modifications may be made therein without departing from the spirit of the invention as set forth in the appended claims.

What is claimed is:

1. In combination with a grenade including a spring loaded arming handle and a firing pin, a means for arming said grenade comprising a length of pyrotechnic Wire adapted to retain said arming handle and firing pin in its unarmed condition, said pyrotechnic wire when ignited acting to burn out along its entire length and release said arming handle and firing pin to function.

2. In combination with a grenade including a container having a main charge therein, a plug secured in said container, a booster charge in said plug, a firing mechanism associated with said plug for firing said booster charge and a spring biased arming handle pivoted on said plug and normally rendering said firing mechanism inoperative; a means for remotely releasing said arming handle to permit functioning of said firing mechanism comprising a length of pyrotechnic wire having one of its ends inserted through said plug and said arming handle, said pyrotechnic Wire, when ignited, adapted to burn throughout its entire length to release said arming handle to initiate operation of said firing mechanism.

3. In combination with a grenade including a container having a main charge therein, a plug having a cut out portion forming a pair of walls in its upper end, a booster charge in said plug, a firing mechanism mounted in said cut out portion and a spring biased arming handle pivotally mounted to said plug and over said firing mechanism and normally rendering said firing mechanism inoperative; a means for remotely releasing said arming handle to permit functioning of said firing mechanism comprising a length of pyrotechnic wire having one end inserted through said walls of said out out portion and said arming handle, said wire adapted, when ignited, to burn its entire length and release said arming handle to initiate operation of said firing mechanism, and means connected to said plug for the sequential firing of other grenades comprising a plurality of pyrotechnic wires radiating from said plug and in communication with said booster charge.

4. A means for remotely arming a grenade as set forth in claim 3 wherein the end of said pyrotechnic wire inserted through said walls of said out out portion and said arming handle is doubled for a distance substantially greater than the width of said walls and said handle.

5. A means for remotely arming a grenade as set forth in claim 3 wherein the end of said pyrotechnic wire inserted through said walls of said cut out portion and said arming handle is contained in a tube fabricated from said pyrotechnic wire.

6. A device of the character set forth in claim 3 wherein said wire is fabricated from a braided combustible cover filled with an ignitable mixture of metal and alloys.

References Cited UNITED STATES PATENTS 1,537,208 5/ 1925 Wiley 102-75 1,543,689 6/1925 Wiley 102-75 1,961,364 6/1934 Hunter 10265 2,763,212 9/ 1956 McCas-lin 102-72 SAMUEL FEIN'BERG, Primary Examiner.

BENJAMIN A. BORCH-ELT, Examiner.

W. KUJAWA, Assistant Examiner. 

2. IN COMBINATION WITH A GRENADE INCLUDING A CONTAINER HAVING A MAIN CHARGE THEREIN, A PLUG SECURED IN SAID CONTAINER, A BOOSTER CHARGE IN SAID PLUG, A FIRING MECHANISM ASSOCIATED WITH SAID PLUG FOR FIRING SAID BOOSTER CHARGE AND A SPRING BIASED ARMING HANDLE PIVOTED ON SAID PLUG AND NORMALLY RENDERING SAID FIRING MECHANISM INOPERATIVE; A MEANS FOR REMOTELY RELEASING SAID ARMING HANDLE TO PERMIT FUNCTIONING OF SAID FIRING MECHANISM COM- 